Sarcoptic mite hypersensitivity and skin lesions in slaughtered pigs

The association between papular skin lesions in slaughtered pigs and hypersensitivity to Sarcoptes scabiei var suis was examined in experimental and field studies, and by the retrospective analysis of monitoring records obtained at slaughter. A causal role for S scabiei was indicated by the production of lesions in experimentally infested pigs, by increased clinical mange in herds having high lesion scores, and by a reduction in the severity of lesions after the implementation of more intensive mange control measures. The specificity of the lesions as an indicator of sarcoptic mite hypersensitivity was estimated to be 0.92 from experimental data and 0.79 from field data. Generalised lesions were rare in mange free pigs, indicating that such lesions were highly specific (1.0 from experimental data, greater than 0.98 from field data) for mange. The assessment of the severity of the lesions in samples of slaughtered pigs appears to be a useful aid to assessing the severity of sarcoptic mange in pig herds.     

Measurements of the degree of development of rigor mortis as an indicator of stress in slaughtered pigs

The degree of development of rigor mortis in the carcases of slaughter pigs was assessed subjectively on a three-point scale 35 minutes after they were exsanguinated, and related to the levels of cortisol, lactate and creatine kinase in blood collected at exsanguination. Earlier rigor development was associated with higher concentrations of these stress indicators in the blood. This relationship suggests that the mean rigor score, and the frequency distribution of carcases that had or had not entered rigor, could be used as an index of the degree of stress to which the pigs had been subjected.     

Hepatitis E virus infection of slaughtered healthy pigs in Brazil

Hepatitis E virus (HEV) is an emerging pathogen that can be transmitted through contaminated raw or undercooked meat derived from domestic pigs. HEV infections have been documented among pig herds, pig products and environmental samples raising concern about the spread of the virus. HEV genotypes 3 and 4 are considered zoonotic and have been linked to human cases. HEV was detected in 51 of 335 bile samples (15.2%) from healthy pigs in Minas Gerais, Brazil. Phylogenetic analysis of partial sequences from ORF1 and ORF2 regions yielded discordant results, assigning isolates to subtypes 3c and 3i, respectively, suggesting intragenotypic HEV recombination.     

Effect of maternal vaccination on the susceptibility of growing pigs to leptospiral infection

Serum samples were collected from 30 piglets, derived from 17 litters, whose dams had been vaccinated against leptospirosis. Microscopic agglutination test (MAT) titres against Leptospira interrogans serovar pomona varied greatly from pig to pig; there was less variation among littermates. Titres declined between 4 and 10 weeks of age, with an uncorrected half-life of 15.5 days, consistent with IgG being the main antibody class involved. Twelve pigs, 4 derived from unvaccinated sows and 8 from sows vaccinated against leptospirosis, were challenged intravenously at 8 weeks of age with leptospires of serovar pomona. Colostrum-derived antibody protected 4 out of 8 pigs, and in 1 of the remaining 4 the serological response was reduced. Three of the protected pigs showed reduced serological responses and in the fourth the response was strong, but delayed. All of the pigs derived from unvaccinated sows developed leptospiraemia and leptospiruria and showed strong serological responses. Protection by colostrum-derived antibody bore an inexact relationship to MAT titre, but a titre of 16 appeared to be sufficient for protection.     

生猪宰后沙门氏菌的实验室检验

沙门氏菌是一种重要的人畜共患传染病的病原,是检疫过程中必须有针对性进行检验的细菌。本文选择沈阳市某屠宰场宰后的可疑生猪5头,无菌采集股内侧肌、淋巴结、肾脏,进行细菌的分离鉴定。通过培养特性、生化特性及血清学鉴定,从2头生猪中检出沙门氏菌,并对其肉品及内脏进行无害化处理。     

Parvovirus infection in pigs with necrotic and vesicle-like lesions

Porcine parvovirus was isolated from many visceral organs and also from the brain, serum and skin specimens of swine with vesicular-like conditions. Severe lesions were reported to have occurred in the mouth, on the tongue and snout, on the coronary band and in the interdigital spaces. Also, parvoviral antigens were demonstrated, by immunofluorescence, in the outer layer of hair follicles in skin adjacent to coronary band lesions.     

Slaughterline records of various postmortem pathological lesions and their influence on carcass and meat quality in slaughtered pigs

The aim of this study was to identify the prevalence of pathological lesions in pigs from small‐scale farms and to determine associations between pathological lesions and hematological parameters, and carcass and meat quality in slaughtered pigs. The study was conducted on 625 pigs (~115 kg) originating from 20 small‐scale farms. Any signs of pneumonia, pleurisy, pericarditis, and liver milk spots were recorded as present or absent. Complete blood count was investigated. The following carcass quality parameters were measured: live, hot and cold carcass weights, cooling loss, dressing percentage, backfat thickness, and meatiness. Meat pH and temperature were measured 45 min postmortem. Of the 625 examined pigs, 41.8% had pneumonia, 23.5% pleurisy, 2.7% pericarditis, and 29.9% liver milk spots. The presence of pathological lesions in slaughtered pigs adversely affected hematological parameters, reduced live, hot and cold carcass weights, and meatiness and had deleterious effects on meat quality (higher pH_45min and higher prevalence of dark, firm and dry meat). In conclusion, this study showed a high prevalence of pathological lesions in slaughtered pigs, indicating serious health problems in smallholder pig production systems. The presence of single and, especially, multiple pathological lesions in slaughtered pigs negatively affected hematological parameters, and carcass and meat quality.     

Prevalence of Toxoplasma infection in cattle slaughtered at an Ohio abattoir.

Specimens of heart, diaphragm and, in 159 instances, esophagus were taken from 352 cattle slaughtered in an Ohio abattoir. The total weight of the material was 32 kg, and this was fed to 12 specific-pathogen-free cats to test for Toxoplasma infectivity. None of the 12 cats acquired Toxoplasma infection, as evidenced by their failure to excrete oocysts or to develop antibodies, and by failure to isolate Toxoplasma from their tissues by inoculation into mice. In further tests, a 650-g sample of beef from 77 of the 352 cattle was digested in 1% trypsin, then inoculated intraperitoneally into 40 mice. Toxoplasma was not isolated from the mice. Serums from 186 of the 352 cattle were inactivated at 60 C for 1 hour, then examined by the Sabin-Feldman (dye) test for antibodies to Toxoplasma. None had titers of more than 1:8. Of the 186 serums, 77 were also examined for antibodies in the indirect hemagglutination test. One had a titer of 1:64, which was considered nonspecific. Thus, evidence for Toxoplasma infection was not found in 352 cattle.     

Multidrug resistance and distribution of Salmonella serovars in slaughtered pigs

The present study was undertaken to estimate the occurrence and distribution of multidrug resistance (MDR) among Salmonella serovars isolated from slaughtered pigs at Debre Zeit, Ethiopia. A total of 501 different samples were examined of which 42 (41.6%) of 101 mesenteric lymph nodes, 22 (21.8%) of 101 tongues, 17 (16.8%) of 101 caecal contents, 11 (11.1%) of 99 livers and two (2%) of 99 muscle (diaphragm and abdomen) samples were Salmonella positive. Of the 94 Salmonella isolates representing 15 different serovars, 69 (73.4%) were multidrug resistant (resistance to two or more antimicrobials). Among the Salmonella serovars a high level of MDR was observed in S. Hadar, S. Kentucky, S. Blockley and S. Enteritidis mainly to tetracycline (88.6%), streptomycin (82.9%), nitrofurantoin (74.3%), nalidixic acid and ciprofloxacin (42.9% each), sulfisoxazole (21.1%) and spectinomycin (20%). The pattern of MDR varied from two to eight antimicrobials among the resistant Salmonella serovars. The common profiles of resistance among the MDR serovars were the combined resistance to nitrofurantoin, streptomycin and tetracycline (R type NitStrTet, 51.4%), ciprofloxacin, nalidixic acid and nitrofurantoin (R type CipNalNit, 10%), ciprofloxacin, nalidixic acid, spectinomycin, streptomycin, sulfisoxazole and tetracycline (R type CipNalSptStrSulTet, 14.3%) and to ciprofloxacin, kanamycin, nalidixic acid, neomycin, nitrofurantoin, streptomycin and tetracycline (R type CipKanNalNeoNitStrTet, 10%). Results of the present study indicate the widespread occurrence and distribution of MDR Salmonella serovars in slaughtered pigs which could be a potential source of human MDR Salmonella infections.     

The first detection of Echinococcus multilocularis in slaughtered pigs in Poland

Alveolar echinococcosis is a serious zoonosis caused by the larval stage of Echinococcus multilocularis. Pigs, as humans, can play the role of non-specific intermediate hosts of this parasite. Detection of E. multilocularis in swine can be taken as an indicator of infection risk for humans. This paper presents the first cases where E. multilocularis larval forms have been detected in pigs in Poland. A total of 256 pig livers with different lesions were collected from slaughterhouses in southern Poland and examined by nested PCR method. Three of them were identified as E. multilocularis positive. They contained noticeable spherical nodular whitish forms on the surface of the liver, recessed partially into the liver tissue. In two cases only single lesions (3mm and 6mm in diameter) were found, while in one case numerous (eight) lesions (2mm in diameter) were found. PCR E. multilocularis identification was confirmed by sequencing and comparison with the GenBank database.     

Detection of leptospiral antigens in kidney and liver of cattle

This study was designed to investigate the presence of leptospiral antigens in kidney and liver of naturally infected cattle using an immunoperoxidase (IP) staining and Levaditi's staining methods. A total of 39 cattle suspected from leptospirosis were examined histologically and immunohistochemically for the presence of leptospiral antigens. The leptospiral antigens were detected in 16 out of 39 cases (seven kidneys, three livers, and six kidneys and livers) when IP staining method was used, whereas leptospiral antigens were detected in 6 out of 39 cases (four kidneys and two livers) when Levaditi's staining method was used. This study ascertained that IP staining was more sensitive method than Levaditi's staining method for demonstrating the presence of leptospirosis in cattle.     

Investigation of possible leptospiral infection in cats in Scotland

Eighty-seven cats from the Glasgow area were investigated to determine the prevalence of leptospiral infection and possible resultant disease. Eight (9-2 per cent) of the cats reacted serologically with the antigens of three serovars. Five of the cats were seropositive to Leptospira hardjo, two to L autumnalis and one cat serocon-verted to L icterohaemorrhagiae. A paired serum sample indicated a recent infection in one of the cats. The major clinical sign shown by this cat was ascites. Four of the cats were from rural areas. This appears to be the first report of a serological survey of leptospiral infection in cats in the Glasgow area.